As preparations are underway for Matthew and Lavinia's wedding, Lady Sybil's attempt to inform her parents of her wish to marry Branson is unsurprisingly met with shock and horror. Robert is violently opposed to the idea but his threats of social disgrace and disinheritance do not dissuade Sybil leading him to try buying off Branson but Branson's intentions are honourable and he refuses. Lady Grantham, Carson and Lavinia are taken ill by the Spanish flu. Thomas' black market venture was a spectacular failure, leaving him penniless and without a job but Carson's illness gives him a chance to become useful in the house. While Lavinia is resting upstairs, Matthew finds himself alone with Mary and tells her what Violet said to him: that he should marry her. Both of them acknowledge he could not as it would be terribly cruel to Lavinia. However, they then kiss just as Lavinia is coming down the stairs. When her illness delays the wedding, Lavinia tells Matthew that she heard and saw everything. She feels they should end their engagement but Matthew refuses. Fearing the outcome of Lavinia’s illness with regard to Matthew and Mary, Richard Carlisle comes to Downton. Daisy is distressed by William’s father’s request to visit him. Ethel is surprised to learn that Major Bryant’s parents want to see her but his father wants to take her child away permanently. Eventually she determines not to let him go as a mother's love is more important than a wealthy upbringing. Robert finds himself unable to control his desire for Jane, who willingly responds. However, their night-time encounter is interrupted and remains unconsummated; and Jane decides to leave. With the possibility of more trouble regarding Vera's death, Anna insists that she and Bates should marry that she may be able to support him through his difficulties as his wife. They marry in secret, with Lady Mary's permission and she arranges for them to spend their wedding night in a guest room. Cora becomes seriously ill and Clarkson fears the worst. O’Brien tirelessly cares for her and tries to ask for her forgiveness. However it is Lavinia who succumbs to the flu and dies saying that it is best for Matthew. Racked with guilt, Matthew tells Mary that any relationship between them is now impossible. Somewhat chastened by the recent events, Lord Grantham reluctantly gives his blessing to Sybil and Branson. The episode ends with Bates’ arrest for the murder of his wife.

David Hinckley

David Wiegand

Fellowes does know how to write some tasty dialogue, especially for Maggie Smith....The other performances are equally winning, but beyond that, you can't help feeling these actors are having a jolly good time with all this overblown fluff. And so will you.

Matt Roush

Watching Downton Abbey is like curling up with a really satisfying book, and I can't think of a better way to get through one of the crueler months of winter. This is one of those shows that after finishing it, I immediately began to envy those who had yet to experience the pleasure.

Brian Lowry

Matthew Gilbert

This extraordinary upstairs-downstairs drama, written by Oscar-winning "Gosford Park" screenwriter Julian Fellowes, is a dramatic, intelligent, soapy, comic, and wise piece of work, one that explores social shifts on the eve of World War I while delivering a remarkably engaging cast of characters.

Rob Owen

Alessandra Stanley

Snobs may sneer that the series could more accurately be called "Remains of the Gosford/Upstairs/Brideshead Revisited Park." But there are times when a sincere imitation is not only better than nothing--it's nearly as good.

Peter Swanson

For every Mrs. Patmore, the cook who wants nothing more than to stay in service the remainder of her life, there is a housemaid such as Gwen (Rose Leslie), who dreams of becoming a secretary in a modern office. It's these dichotomies, and the way they exist within both the Abbey itself (half the rooms have electricity and half don't) and its multifaceted inhabitants that make Downton Abbey not only the best soap opera currently on television, but one of the most relevant as well.

Jeanne Jakle

Mark Dawidziak

If some plot elements in the third season seemed forced (and they did), then Fellowes seems to have completely regained his balance in the fourth season. And that balance means expertly bouncing between the upstairs and downstairs worlds of Downton, letting the plot turns flow naturally, carrying us along joyously for the posh ride.

June Thomas

Ellen Gray

It's quibbling to say that it feels at times as if Downton Abbey had been custom-designed for those of us for whom period romance is mother's milk, studded as it is with plucky heroines, accidental heirs and scheming dowagers, with just enough history thrown in to make the melodrama seem highbrow. It's not, really, though. It's simply delicious fun.

Alan Sepinwall

Now, I wouldn't say I loved it. Parts of it I didn't even like. I became quite engaged with what was going on downstairs with the servants, while I found virtually everything having to do with the Granthams (at least the parts unrelated to how they dealt with the staff) a chore to get through.